Plastic container with reinforced panel

ABSTRACT

The invention relates to a plastic recipient comprising a panel with at least one radius of curvature greater than 100 mm, where the panel has reinforcing means. The reinforcing means includes a peripheral slot defining a reinforcing contour and a plurality of inner slots arranged inside the reinforcing contour. Each inner slot has two ends, where each end opens out into the peripheral slot, or at least one end opens out into another inner slot.

The domain of the invention is the design and manufacture of recipientsmade of plastic material obtained by blowing or stretch-blowing in aforming die.

More specifically, the invention relates to a recipient having asubstantially rectangular or oval section. This type of plasticrecipient usually has at least one wall provided with a “flat” panel,i.e. a panel with a surface usually used to receive a label.

“Flat panel” can mean an actually flat panel, but also a slightly curvedor domed panel with one or more radii of curvature such that the panelappears flat (for example one or more radii of curvature equal to orgreater than 100 mm).

To ensure that the recipient is sufficiently rigid, it is known toincrease the thickness of the material in the walls of the recipient.However, there is a particular trend towards reducing the weight ofrecipients, and notably reducing the thickness of the walls of therecipient.

Indeed, by reducing the thickness of the walls and therefore thematerial used, it is possible to reduce the weight of the recipients andto reduce the production cost thereof.

Furthermore, reducing the material and therefore the weight of therecipients is beneficial in environmental terms since less plastic isused and less energy is required to manufacture a recipient. This isnotably because the pressure of the air injected to form a recipient canbe reduced without adversely affecting the quality of the obtainedrecipient.

However, reducing the thickness of the walls of the recipients causesproblems in terms of the mechanical strength of the recipients. This isnotably the case for recipients with a flat panel. In particular, whenthe recipient is removed from the forming die, the flat panels aredeformed, notably by warping.

This phenomenon is particularly pronounced in recipients that have ahandle as well as the flat panel, since the presence of the handleincreases the stresses in the plastic, notably PET.

At least two solutions have been proposed to prevent the deformation offlat panels.

A first solution involves heating the walls of the die that define theshape of the formed recipient.

Heating the walls of the die, usually between 10° and 65° (and morespecifically about 35°) helps to facilitate contact between the plasticand the die.

However, heating the die increases the phenomenon of shrinkage of theplastic following removal from the die.

Thus, if the material fits the walls of the die during molding, saidmaterial contracts when the formed recipient is removed from the die.This causes a loss of definition in the details of the recipient,notably structured pattern details including low-radius curves, whichare the most difficult curves to obtain. The formed recipient thencorresponds in general to the imprint of the die with the exception ofcertain details that are formed in the die but that disappear from therecipient following removal from the die as a result of shrinkage of thematerial.

In other words, the fact of heating the die prevents the plasticmaterial, notably PET, from setting against the walls of the die.Following removal from the die, shrinkage then causes the precise formsto disappear from the recipient.

The second solution involves providing the flat panel with reinforcingmeans. These reinforcing means are conventionally slots formed in theflat panel, said slots usually being parallel with one another andequidistant from one another.

This second solution helps to keep manufacturing costs substantially thesame as with conventional manufacturing.

Conversely, such slots need to be somewhat deep to be effective, and assuch are visible beneath the labels of the recipients.

Furthermore, these slots are usually positioned such that the panel canonly be deformed along a single axis of deformation. Consequently,deformation along another axis of deformation is possible. In general,where the slots are positioned substantially perpendicular to thelongitudinal axis of the recipient, the deformations occur between theslots. Conversely, where the slots are positioned substantially parallelwith the longitudinal axis of the recipient, the deformations occur atthe ends of the slots.

The invention is notably intended to overcome the drawbacks in the priorart.

More specifically, the invention is intended to propose a recipient madeof plastic material with a flat panel that is susceptible to limited, orat least controlled, deformation, so as to obviate any loss of qualitythat could be perceived by a consumer, as well as enabling the recipientto be labeled.

The invention is also intended to provide such a recipient that issimple to manufacture and notably adaptable to a conventional productionmethod.

The invention is also intended to provide such a recipient in which theflat panel has reinforcing means that are invisible or nearly invisiblebeneath the label.

These objectives and other objectives set out below are achieved by theinvention, which relates to a plastic recipient including a panel withat least one radius of curvature greater than 100 mm, the panel havingreinforcing means, characterized in that the reinforcing means include:

-   -   a peripheral slot defining a reinforcing contour,    -   a plurality of inner slots arranged inside the reinforcing        contour, each inner slot having two ends, each end opening into        the peripheral slot, or another inner slot.

The peripheral slot delimits a reinforced zone of the flat panel. A zonethus delimited concentrates the deformation stresses therein, therebyhelping to improve the quality perceived by the consumer.

The inner slots make the zone surrounded by the peripheral slot morerigid, thereby making the entire flat panel more rigid.

Furthermore, the fact that the inner slots open out into the peripheralslot or into another inner slot also enables the flat panel to helpretain the shape of the recipient (i.e. the flat panel helps to preventthe overall deformation of the recipient).

According to a first advantageous embodiment, the peripheral slotdefines a closed reinforcing contour.

The closed contour provides an additional guarantee in terms ofresistance to deformation of the flat panel.

Furthermore, the closed contour delimits a labeling zone, i.e. a zonereserved for sticking the label about the reinforcing means.

According to another advantageous embodiment, the peripheral slotdefines an open reinforcing contour.

An open reinforcing contour also provides the flat panel with goodrigidity. Short openings in the contour are nonetheless preferred tolong openings, which increase the risk of deformation of the flat panel.

Consequently, the discontinuity of the peripheral slot enables therecipient to be deformed deliberately to remove the product containedtherein.

Advantageously, the inner slots are arranged to form a lattice pattern.

The lattice pattern helps to make the flat panel more rigid alongseveral axes. The lattices help to increase the quality of the recipientas perceived by the consumer. Furthermore, if the label is removed orcomes unstuck, the lattice pattern gives the recipient a pleasingesthetic effect.

In this case, the inner slots are advantageously rectilinear.

The straightness of the inner slots increases the perceived quality ofthe recipient and notably the rigidity of the flat panel.

In a variant, the inner slots are curvilinear.

Such inner slots thus retain stiffening properties, while providingdecoration, notably if the label is removed and the reinforcing meansare revealed, or in recipients with specific shapes such as roundedshapes.

Preferably, the inner slots include:

-   -   a first series of slots that are parallel with one another and        oriented in a first direction at an angle to the longitudinal        axis of the recipient,    -   a second series of slots that are parallel with one another and        oriented in a second direction at an angle to the longitudinal        axis of the recipient.

Such an arrangement of the inner slots helps to form the latticepattern. Furthermore, such an arrangement of the inner slots forms aregular mesh, i.e. the surfaces between the inner slots aresubstantially identical.

According to a preferred embodiment, the depth of the peripheral slot isbetween 0.3 mm and 1.5 mm.

This depth range helps to provide the peripheral slot with goodstiffening properties without becoming visible beneath the label.

For the same reasons, it is preferable for the depth of each inner slotto be between 0.3 mm and 1.5 mm.

Advantageously, the ratio PRP/PRI between the reinforcing means isbetween 0.8 and 2.4, where:

-   -   PRP: depth of the peripheral slot,    -   PRI: depth of the inner slots.

This ratio between the depths of the inner slots and the peripheral slothelps to provide good uniformity and stiffening, and notably helps toprevent the peripheral slot or the inner slots from being too flexiblein relation to one another. This prevents the phenomenon of combinedrigidity and flexibility, which could adversely affect the quality ofthe recipient as perceived by the consumer.

Preferably, the width of the peripheral slot is between 100% and 300% ofthe depth thereof, and preferably 200% of the depth thereof, and/or thewidth of each inner slot is between 100% and 300% of the depth thereof,and preferably 200% of the depth thereof.

Such a correlation between the depth and width of the slots helps toprovide rigid outer and inner slots. This improves the rigidity of theflat panel and reduces the deformation thereof.

Advantageously, the lattice pattern defines a plurality of fullsurfaces, each of which is delimited by four inner slots, each fullsurface having an area of between 150 mm² and 1000 mm².

An area of the full surfaces of between 150 mm² and 1000 mm² provides atight mesh that is not too rigid

Preferably, the ratio between the areas of two adjoining full surfacesis between 0.5 and 1.5.

This enables a certain uniformity of the stiffening of the flat panel,while enabling manufacturing tolerances that can mean that the areas ofthe flat surfaces different.

Preferably, the plastic recipient includes a label covering the panel,the reinforcing means extending over a surface covering between 55% and90% of the surface of the label.

Thus, the reinforcing means are entirely hidden beneath the label.

Other features and advantages of the invention will become more clearlyapparent on reading the description of a preferred embodiment, givenbelow by way of non-limiting example, and the attached drawings, inwhich:

FIG. 1 is a front view of a plastic recipient according to theinvention, in which the recipient has a panel including reinforcingmeans,

FIG. 2 is a schematic front view of reinforcing means according to afirst embodiment,

FIG. 3 is a schematic front view of reinforcing means according to asecond embodiment,

FIG. 4 is a schematic front view of reinforcing means according to athird embodiment,

FIG. 5 is a schematic cross-section view of the reinforcing meansaccording to a first embodiment,

FIG. 6 is a schematic cross-section view of the reinforcing meansaccording to a second embodiment,

FIG. 7 is a schematic cross-section view of the reinforcing meansaccording to a third embodiment.

FIG. 1 shows a recipient 1 made of plastic material according to theinvention.

The recipient 1 comprises a neck 11, a bottom 12 and a body 13 joiningthe bottom 12 and the neck 11.

The neck 11 has a rim 111 acting as interface between the inside of therecipient 1 and the outside. The neck 11 also has retaining means 112(such as a thread) designed to cooperate with plugging means (such as ascrew cap), not shown in FIG. 1.

Finally, the neck 11 has a flange 113 that is designed to enable theneck 11 to be gripped when leaving a manufacturing unit of the recipient1. This flange 113 is present on the preform used to obtain therecipient 1 and is also used to handle the preform before manufacture ofthe recipient.

The bottom 12 has a resting plane 121 on which the recipient 1 isdesigned to rest, for example on a table.

The body 13 has a substantially parallelepipedic section with two longsides and two short sides, the long sides and the short sides facing oneanother in pairs.

FIG. 1 is a front view of the recipient 1. The visible face in FIG. 1shows a panel 14 notably designed to be covered by a label 15.

The panel 14 has a radius of curvature greater than 100 mm.

Furthermore, the body 13 has a handle 131 that is designed to help auser to grip the recipient 1.

A flat recipient according to the prior art, often referred to as a flatbottle on account of the geometry thereof and notably theparallelepipedic section thereof, can have certain esthetic defects,notably warping on the panel thereof.

In order to prevent such warping and to ensure a good overallappearance, the recipient 1 according to the invention has reinforcingmeans 16 for the panel 14.

Preferably, the ratio between the surface covered by the reinforcingmeans 16 and the total surface area of the panel 14 is between 55% and90%.

As shown in FIG. 1, the reinforcing means cover approximately 75% of thesurface area of the label 15.

In general and as shown in the figures, the reinforcing means 16comprise a peripheral slot 160 defining a substantially rectangularreinforcing contour and a plurality of inner slots 161, 162. Byconvention, in the remainder of the description, the side of therectangular shape defined by the peripheral slot 161 that is visible atthe top of this shape in the figures is referred to as the “top side”,the side visible on the bottom of this shape in the figures is referredto as the “bottom side”, the side visible on the left of this shape inthe figures is referred to as the “left-hand side”, and the side visibleon the right of this shape in the figures is referred to as the“right-hand side”.

More specifically and as shown in FIGS. 1, 2 and 3, the peripheral slot160 is continuous and defines a rectangular closed contour with roundedcorners.

In a variant and as shown in FIG. 4, the peripheral slot 160 isdiscontinuous and defines an open contour.

Furthermore, the reinforcing means 16 include a plurality of inner slots161, 162 that are arranged in two series inside the peripheral slot 160and that can be formed in various different ways, as shown in FIGS. 1 to4.

According to a first embodiment illustrated in FIG. 1, the inner slots161, 162 are arranged to form a lattice pattern defining a plurality offull surfaces 17 and truncated surfaces 18, i.e. surfaces cut off by theperipheral slot 160.

Preferably, each full surface 17 has a surface area of between 150 mm²and 1000 mm², and the area ratio between two adjoining full surfaces 17is between 0.5 and 1.5.

More specifically, the inner slots 161, 162 are all rectilinear andarranged as follows:

-   -   a first series S1 of inner slots 161 that are parallel with one        another and extend in a first direction A,    -   a second series S2 of inner slots 162 that are parallel with one        another and extend in a second direction B perpendicular to the        first direction A.

Preferably, the first direction A is at an angle to the longitudinalaxis X of the recipient. The second direction B is perpendicular to thefirst direction A such as to also be at an angle to the longitudinalaxis X of the recipient, albeit in a different direction. In otherwords, the inner slots 161 of the first series S1 are perpendicular tothe inner slots 162 of the second series S2.

Preferably, the first direction A is at an angle of approximately 45° tothe longitudinal axis X of the recipient such that the second directionB is at a similar angle.

According to a second embodiment illustrated in FIG. 2, the inner slots161, 162 of each series are formed using curved lines. In other wordsand unlike the first embodiment, the inner slots 161, 162 are notrectilinear.

More specifically, the reinforcing means 16 according to this secondembodiment comprise a first series S3 of inner slots 161 that areparallel with one another and a second series S4 of inner slots 162 thatare parallel with one another, the first series S3 and the second seriesS4 being arranged at substantially 90° to one another.

According to a third embodiment illustrated in FIG. 3, the inner slots161, 162 of the reinforcing means 16 comprise a first series S5 of innerslots 161 that are parallel with one another and a second series S6 ofinner slots 162 that are also parallel with one another andperpendicular to the inner slots of the first series.

Unlike in the first embodiment, the inner slots 162 of the second seriesS6 are staggered on either side of an inner slot 161 of the first seriesS5.

In other words and as shown schematically in FIG. 3, each of the innerslots 161 of the first series S5 links two sides of the contour formedby the peripheral slot 160. These sides may be two opposing sides or twoadjacent sides. Some of the inner slots 162 of the second series S6 arearranged between two inner slots 161 of the first series S5, and othersare arranged between one inner slot 161 of the first series S5 and oneor other of the sides.

Thus, the following arrangement is shown in FIG. 3, purely by way ofexample:

-   -   a first inner slot 161 of the first series is shown with the two        ends 161 a and 161 b thereof opening out respectively into the        top side and the left-hand side of the contour formed by the        peripheral slot 160,    -   a second inner slot 161 of the first series is shown with the        two ends 161 a and 161 b thereof opening out respectively into        the right-hand side and the bottom side of the contour formed by        the peripheral slot 160,    -   some of the inner slots 162 of the second series S6 are arranged        between two inner slots 161 of the first series S5, and others        are arranged between one inner slot 161 of the first series S5        and one side (or a corner of the contour).

It should be noted at this point that in an actual implementation of thethird embodiment, the first series S5 would have a considerably largernumber of inner slots 161 than the two inner slots 161 shown in FIG. 3.Similarly, an actual implementation would involve many more inner slots162 in the second series S6 than those shown in the figure.

It should also be noted that, instead of opening out into two adjacentsides of the contour, an inner slot 161 of the first series S5 could:

-   -   be arranged on a diagonal of the contour and open out into two        opposing corners or,    -   have one of the ends 161 a or 161 b thereof open out into a        corner of the contour and the other end 161 a or 161 b open out        into one of the sides opposite this corner. Furthermore, or in        addition to the foregoing, one or more inner slots 161 of the        first series S5 could open out into two opposing sides of the        contour, while one or more other inner slots could open out into        adjacent sides.

According to a fourth embodiment illustrated in FIG. 4, the peripheralslot 160 has a contour opened in several places (corner(s) and/orside(s)) and the reinforcing means 16 form a lattice pattern similar tothe pattern in FIG. 1. At least two additional inner slots 164 arearranged substantially along the longitudinal axis X of the recipient 1,as shown in FIG. 1, and oriented from bottom to top in consideration ofthe normal position of a recipient placed on the base thereof. In thisexample, just two have been added.

The set of inner slots in this fourth embodiment thus form differentsurfaces, including at least:

-   -   a triangular surface 171 delimited either by a portion of the        peripheral slot 160 and portions of two inner slots,        specifically two of the inner slots 161, 162 or 164, or by        portions of three inner slots 161, 162, 164,    -   a quadrilateral surface 172 delimited either by a portion of the        peripheral slot 160 and portions of three inner slots 161, 162,        164, or by portions of two inner slots 161 and two inner slots        162,    -   a pentagonal surface 173 delimited either by a portion of the        peripheral slot 160 and four portions of inner slots 161, 162,        164, or by five portions of inner slots 161, 162, 164,    -   a hexagonal surface 174 delimited either by the peripheral slot        160 and five portions of inner slots 161, 162, 164, or by six        portions of inner slots 162.

With reference to FIGS. 5, 6 and 7, the depth PRI of each inner slot161, 162, 164 is between 0.3 mm and 1.5 mm. Advantageously, the depthPRI of each inner slot 161, 162, 164 is 0.5 mm.

Similarly, the depth PRP of the peripheral slot 160 is between 0.3 mmand 1.5 mm. Advantageously, the depth PRP of the peripheral slot 161,162, 164 is 0.8 mm.

According to one aspect of the invention, the reinforcing means 16define a ratio between the depth PRP of the peripheral slot 160 and thedepth PRI of the inner slots 161, 162, 164 of between 0.8 and 2.4.

Preferably, the ratio PRP/PRI of the depth PRP of the peripheral slotdivided by the depth PRI of the inner slots 161, 162, 164 is 1.6.

Advantageously, the width of each inner slot 161, 162, 164 is between100% and 300% of the depth PRI thereof, and preferably 200% of the depthPRI thereof.

Similarly, the width of the peripheral slot 160 is between 100% and 300%of the depth PRP thereof, and preferably 200% of the depth PRP thereof.

According to a first embodiment illustrated in FIG. 5, the depth PRI ofthe inner slots 161, 162, 164 is less than the depth PRP of theperipheral slot 160.

According to a second embodiment illustrated in FIG. 6, the depth PRI ofthe inner slots 161, 162, 164 is equal to the depth PRP of theperipheral slot 160.

Finally, according to a third embodiment illustrated in FIG. 7, thedepth PRI of the inner slots 161, 162, 164 is greater than the depth PRPof the peripheral slot 160. However, in this third embodiment, each ofthe inner slots 161, 162, 164 has a sloping portion 165 at each of theends thereof that opens out into the peripheral slot 160, enabling thedepth PRI of said end opening out into the peripheral slot 160 to beequal to the depth PRP of the peripheral slot 160. The sloping portions165 thus obviate all molding issues.

The reinforcing means 16 help to create a stiffening structure thatprevents the panel 14 from becoming deformed when taken out of the mold,i.e. when the material used to make the recipient 1 is close to theglass transition temperature at which said material deforms easily.

Furthermore, although not the primary objective, once the recipient 1has been cooled, filled and plugged, the reinforcing means 16 can helpto provide the plastic recipient 1 with an aesthetically pleasing shape.

In the absence of reinforcing means 16, the recipient 1, and notably thepanel 14, can warp and make the recipient 1 unsightly.

The reinforcing means 16 are notably designed to be covered by a label15, notably showing the characteristics and/or the brand of the productcontained in the recipient 1. However, the reinforcing means 16 can alsobe positioned in a zone of the recipient 1 that has a panel not coveredby a label 15.

Advantageously, the dimensions of the reinforcing means 16 are less thanthe dimensions of the label 15 and are more specifically between 0.5 mmand 1 mm less than the dimensions of the label, which corresponds forexample to a coverage of approximately 90% of the surface of the label15.

Although FIGS. 1 to 4 show embodiments in which the peripheral slot 160is substantially rectangular, all other shapes (for example ovoid, roundor indeterminate), can be used to form the open or closed contour of thereinforcing means.

Similarly, the reinforcing means 16 can be incorporated into a recipient1 with no handle 131.

Furthermore, the recipient 1 according to the invention can also have asecond peripheral slot (not shown in the figures) surrounding the firstperipheral slot 160.

Finally, some of the inner slots 161, 162, 164 can be rectilinear whileothers are curved.

The plastic recipient 1 according to the invention provides theadvantage of enhanced reinforcement of the panel 14 compared to theprior art.

Indeed, the presence of the peripheral slot 160 and of the inner slots161, 162, 164 opening out into the peripheral slot 160 or into anotherinner slot 161, 162, 164 helps to stiffen the panel 14, notably toprevent the panel from warping when removed from the mold.

Furthermore, the depths PRP, PRI of the peripheral the internal slots160, 161, 162, 164 are selected so as not to be visible when the label15 is glued to the recipient 1.

1. A recipient (1) made of plastic material comprising a panel (14) withat least one radius of curvature greater than 100 mm, the panel (14)having reinforcing means (16), wherein the reinforcing means (16)include: a peripheral slot (160) defining a reinforcing contour, and aplurality of inner slots (161; 162) arranged inside the reinforcingcontour, each inner slot (161; 162) having two ends (161 a; 161 b; 162a; 162 b), each end opening into the peripheral slot (160), or at leastone end (162 a; 162 b) opening out into another inner slot (161).
 2. Theplastic recipient (1) as claimed in claim 1, wherein a peripheral slot(160) defines a closed reinforcing contour.
 3. The plastic recipient (1)as claimed in claim 1, wherein the peripheral slot (160) defines an openreinforcing contour.
 4. The plastic recipient (1) as claimed in claim 1,wherein the inner slots (161; 162) are arranged to form a latticepattern.
 5. The plastic recipient (1) as claimed in claim 1, wherein theinner slots (161; 162) are rectilinear.
 6. The plastic recipient (1) asclaimed in claim 1, wherein the inner slots (161; 162) are curvilinear.7. The plastic recipient (1) as claimed in claim 1, wherein the innerslots (161; 162) include: a first series (S1) of inner slots (161) thatare parallel with one another and oriented in a first direction (A) atan angle to a longitudinal axis (X) of the recipient (1), and/or asecond series (S2) of inner slots (162) that are parallel with oneanother and oriented in a second direction (B) also at an angle to alongitudinal axis (X) of the recipient (1).
 8. The plastic recipient (1)as claimed in claim 7, further comprising at least two additional innerslots (164) extending substantially along the longitudinal axis (X) ofthe recipient (1).
 9. The plastic recipient (1) as claimed in claim 1,wherein the depth (PRP) of the peripheral slot (160) is between 0.3 mmand 1.5 mm.
 10. The plastic recipient (1) as claimed in claim 1, whereinthe depth (PRI) of each inner slot (161; 162) is between 0.3 mm and 1.5mm.
 11. The plastic recipient (1) as claimed in claim 1, wherein theratio (PRP/PRI) of the reinforcing means (16) is between 0.8 and 2.4,where: (PRP): depth of the peripheral slot (160), and/or (PRI): depth ofthe inner slots (161; 162).
 12. The plastic recipient (1) as claimed inclaim 1, wherein the width of the peripheral slot (160) is between 100%and 300% of the depth (PRP) thereof, and preferably 200% of the depth(PRP) thereof.
 13. The plastic recipient (1) as claimed in claim 1,wherein the width of each inner slot (161; 162; 164) is between 100% and300% of the depth (PRI) thereof, and preferably 200% of the depth (PRI)thereof.
 14. The plastic recipient (1) as claimed in claim 4, whereinthe lattice pattern defines a plurality of full surfaces (17), each ofwhich is delimited by four inner-slot portions (161; 162), each fullsurface (17) having an area of between 150 mm² and 1000 mm².
 15. Theplastic recipient (1) as claimed in claim 14, characterized in that theratio between the areas of two adjoining full surfaces (17) is between0.5 and 1.5.
 16. The plastic recipient (1) as claimed in furthercomprising a label (15) covering the panel (14), the reinforcing means(16) extending over a surface covering between 55% and 90% of thesurface of the label (15).